Sheet-end indicator and space counter for printing machines



19, 1952 P. F. GUERIN ,607,

SHEET-END INDICATOR AND SPACE COUNTER FOR PRINTING MACHINES Filed Feb. 18, 1950 z Sheets-Sheet 1 l VENTOR Pmv/ 621E777? I TTORNEYS Aug. 19, 1952 P. F. GUERIN 2,607,465

SHEET-END INDICATOR AND SPACE COUNTER FOR PRINTING MACHINES Filed Feb. 18, 1950 5 Sheets-Sheet 2 FIG. 3

l VENTOR Pau/ Que/'1' ATTORNEYS Aug. 19, 1952 P. F. GUERIN 2,607,465

SHEET-END INDICATOR AND SPACE COUNTER FOR PRINTING MACHINES Filed Feb. 18, 1950 5 Sheets-Sheet 5 IN E TOIR Paul z/erz'n 11+ Maw ATTORNEYS Patented Aug. 19, 1952 UNITED 1 SHEET-END INDICATOR AND SPACE COUNTER FOR PRINTING MACHINES Paul F. Guerin, Paris, France Application February 18, 1950, Serial No. 144,939

14 Claims. 1

My invention is concerned with a sheet-end indicator and line or space counter to be used generally on all machines for printing sheets of variable lengths when the sheet is driven by a cylinder, and in particular on typewriting machines.

Various kinds of sheet-end indicators have been proposed for warning the operator of the approaching end of the sheet of paper being typed upon. Some of these indicators warn-the operator by a single signal, for example the appearance of a red dot in a visor, of the approaching end of the sheet. Such indicators have the great disadvantage of not enabling the operator, within a sufficiently large range (for example, twenty single-space lines), to ascertain the exact posi-' tion of any line in relation to the approaching end of the sheet.

Some counters have been proposed which provide within a certain range, a continuous system for counting the number of lines remaining available until the end of the sheet is reached. In spite of the desirability of having counters or indicators of this type, typewriters now in commercial use are, to the best of my knowledge, still not provided with them. This may be due to the fact that this type of indicator presents a certain degree of complexity, but also, and more likely, this maybe due to theabsence of means providing for the free and absolutely unimpeded movement of the sheet or sheets of paper during a return or reverse movement.

In a proposed form of counting indicator of this type, the mechanism is driven by a combina tion of the movements of the paper and of the platen, the movement of the paper being transmitted to a roller which presses the sheet or sheets against the guide plate of the typewriter. When the paper has passed under the roller it is an essential condition of the functioning of that counter that the roller remains braked by pressing upon the guide plate. However, when the operator reverses the movement of the platen for making a correction on the sheet, or for any other purposes, the presence of theroller-and its pressure on the guide plate'is likely to prevent the free reverse movement of the paper. This is a particularly important obstacle to the return of thin and flexible sheets of paper for re-engagement under the roller and to the driv ing of the roller by the reverse movementof-the sheets. I

The primary objects of my invention, among others, are to provide a wide range of action in counting in both directions, simplicity of construction, ease of adaptation in typewriter's'and and to provide a space or line counter driven by the platen alone during all reverse movements of the sheet or sheets of paper. This last feature permits the use of a mechanism responsive to changes in the direction of rotation of the platen, the purpose of which is to disengage the roller driven by the sheet being printed and to hold it removed therefrom as long as the reverse movement of the paper lasts. The roller is there fore held in a position where it cannot hamper the reverse movement of the sheet or sheets, and I provide mechanism adapted to return the roller to its former position when the platen and the paper are again moved in a forward direction.

In order to accomplish certain of these functions I provide for a single means for accomplishing a locking action on the mechanism driven by the sheet and roller instead of relying upon the braking action of the roller to efiect operation of the counting mechanism per se to count the lines or spaces remaining on the sheet after the sheet has moved from under the roller. This locking action, as will be seen in the following description-of the movements of the apparatus, allows a succession of engagements and disengagements of the roller to take place at each change in the direction of rotation of the platen and of the sheet without interfering with the counting operation.

The relative simplicity and small space occupied by my counting mechanism is obtained by means of using only one differential gear train and by the relatively simple means adopted to effect the automatic return of the counter to its initial or starting position when the operator has reached the end of the sheet.

In general, the counting and indicating mechanism of my invention includes a counting means and means responsive to the rotation of the cylinder or platen of a printing machine and to amean'sqsuch as a roller actuated by the movementflo-f a sheet of paper moving over the cylinderv and being printed upon, said mechanism including'mea-nsfor effecting the following operations or conditions:

(l) preventing the operation of thecounting means while the mechanism is driven in a forwarddirection both by the cylinder and by the roller actuated bythe sheet, as long as the sheet is engaged by the roller;

preventing the operation of the counting means during any further backward movementpassing between the roller and guide plate willrotate the roller, and, through associated means, operate the part of the mechanism referred to above. In this construction I advantageously mount the roller on a pivoted frame and provide means directly responsive to reverse rotation of the cylinder or platen for swinging the roller away from the sheet or sheets of paper on the guide plate. 7

My. indicating and counting mechanism also advantageously comprises a differential gear train. including a pair of parallel bevel gears of equal diameter meshing with an intervening pinion gear. Means is provided for driving one of the bevel gears from the cylinder or platen and means is provided for driving the other bevel gear from the roller when itis engaging the paper on the guide plate in the printing machine. These means are. arranged so that the bevel gears are driven at the same rate and in opposite directions during the operation of the typewriter while the paper is under the roller. In this operation the pinion gear merely rotates in place. After the paper is moved from under the roller, however, itiwill no linger rotate and. therefore thepinion gear will be displaced. I therefore ad vantageously provide a shaft axially of the bevel gears having a fixed radially-extending arm servingas an axle on which the pinion gear is mounted. When the pinion gear is displaced, it rotates the shaft extending through the bevel gears and through suitable mechanism operates the counting means to count the lines or spaces remaining on the sheet. In my apparatus I provide means operative upon the initial movement of said shaft forilocking the bevel gear previously driven by the roller.

The preferred form of mechanism also includes means for automatically returning the pinion gear and the counter to its starting or initial position. One form of such construction comprises means operatively associated with the pinion gear axle for disconnecting the driving connection between the cylinder or platen and its bevel gear, means for moving the pinion gear to its initial position, and means operative upon return of the pinion gear to its starting position-for tural forms thereof may be made... The detailed features of the invention are described herein in 4 connection with the accompanying drawings forming a part of this application.

In the drawings:

Fig. 1 is a broken front elevational view of the upper front portion of a typewriter showing the indicator mechanism of my invention attached thereto.

Fig. 2 is a broken sectional view on an enlarged scale taken on the line 2.-2 of Fig. l.

Fig. 3 is a front elevational view partly in section, taken on the irregular line 3-3 of Fig. 2.

Fig. 4 is a broken view similar to that of Fig. 2 showing the arrangement of the means for disconnecting the driving connection between the typewriter platen and the indicator mechanism.

Fig. 5 is a broken vertical sectional view taken on the line 55 of Fig. 4.

Fig. dis a broken detailed view of a part of the mechanism shown in Figs. 4 and 5 taken. on the line 6-5 of Fig. 5.

Fig.7 is a broken vertical sectional view showin a part of the mechanism of Fig. 2 in a different stage of operation.

Fig. 8 is a view similar to Fig, 5 showing a changed position for certain of the elements.

Fig. 9 is a view similar to that of Fig. "6 showing. a changed position for certain of the elements. I

Fig. 10is an elevational view showing a modified form of driving means associated with a cylinder or platen.

Fig. 11 is a broken sectional View taken on the line ll-Il ofFig. 10.

Fig. 1 of the drawings shows my improved sheet-end indicator and counter 15 as an attachment applied to the right-hand side of a typewriter of conventional design including a cylinder or platen l6 mounted in a carriage frame I? and having a cylinder knob 18. Also shown is the paper guide plate l9 which extends around the' back and under-portion of the cylinder 16. A sheet of paper 20 is shown in the typewriter.

The counting mechanism is operatively connected to the platen by providing on the righthand end of the cylinder a gear wheel 2! meshing with a small gear wheel 22 carried thereon and adapted to rotate a square shaft 23 extending across the typewriter carriage and having its ends rotatably mounted in bearings 24 in the side frame members of the carriage. .The'square shaft 23 extends through the lower portion of the counting mechanism l5 and supports the front portion of a casing 25. The shaft 23 operates parts of the mechanism I5 by means of gear wheels carried by the shaft and described in detail hereinafter. Another portion of the mechanism i5 is operated by a roller 26 which normally presses against the sheet of paper 20 and is rotated by the movement of the paper during a portion of the normal typing operation. The casing 25 carries a dial housing 21 having a window through which the operator may observe the number of remaining spaces or the lines remaining tobe typed on the sheet 20.

From the showing in Fig. 2 it will be noted that the casing 25 is secured to the upper portion of the guide plate H! by a member 28 which engages both the inner and the outer portions of the guide plate and which is slidable thereon so that the mechanism [5 may be slid along the square shaft 23 and the guide plate i 9 to position the roller- 26 on the marginal portion of the sheet 20 to the extent desired, according to the width of the paper to be used in the typewriter.

. Referring to Figs. 2 and 3 of the drawings, the

' with respect to the shaft 29- and carrying in their outer ends a rotatable shaft 32 on one end of which the roller 26 is fixed.

'Ihe shaft 2-9 also carries a differential gear system including a pair of parallel bevel gears 33 and 34 of equal diameter which have peripheral gear} teeth and inner bevel gear teeth-the latter meshing with a satellite or pinion gear 35"whi'ch is rotatably mounted on a shaft or arm 36 fixed to the shaft 29. The peripheral gear teeth of the gear 34 mesh with the gearteeth of a gear 31Tfixed to the shaft 3'2s0 thatrotation of the-roller 23 causes rotation of the gears 31, 34 and 3'5. The peripheral gear teeth of the gear 33 mesh with the gear teeth of a small'gear 38 carried on the shaft '23, as shown in Fig. 4, and described more in detail'hereinafter. j

The means for controlling the swinging move merits of the roller .26, and particularly for retracting theroller automatically, are shown in Figs. 2 and 3 of the drawings inconnection with the'parallel axles or shafts 29 and 32. At the right side of the mechanism atriangular frame is'provided at a right angle to the supporting frame, in which thelink 3| is the diagonal mem-: ber, :a link 39 is thehorizontal member, and a link 40 is a vertical member. The links 39 and 40 have ends respectively 'carried on the shafts 32 and 29 and in which such shafts are rotatable. The other ends of the links 33 and 43 are loosely clamped together by a screw or rivejt 41, the

shank of which is slidable laterally againsta spring 42 in a slot in the link 39. The links-39 and '40 may be slotted and tubular so as to suitably retain the springs as shown. ,Thelink 40 carries two spring 43' and 44 bearing against a movable member pivoted to one end of a lever 45 which is pivoted to the side of the-casing -25 by a pivot member 46. The-lower end of the lever 45 engages in a star wheel 41 mounted-for rotation on and with the-square shaft 23.;

When'the cylinder I6 is reversed by the op erator, the starwheel 4'l rocks the lever 45 on itspivot and quickly swings the roller 26 on its supporting frame away from the guide plate l9 so that the roller does not interfere with the re.- tra-ction of the sheetor sheets of p-aperin the typewriter. When the typewriter is operated under normal conditions, the star wheel 41 rotates counter-clockwise and urges the lower end of the lever 40 to the right in Fig. 2 and thereby maintains a tension on the spring 42 which urges the roller 26 resiliently againstthe paper or the guide plate l9. I a j The roller 26 is of such diameter and the various gears are correlated with respect to each other and the diameter of the cylinder 16 so that while the parallel gears 33 and 3-4 are. being respectively driven by the platen and the roller; they will rotate in Opposite directions andat the same rate so that the satellite gear 35 will rotate in place without moving through an arc. How ever, the mechanism is'arranged so that when the'end of. the paper, such as the sheet v20, in the normal course of a typing operation, passes under the roller 26, the rollerstops rotation and also stops rotation of the gear 34. The satellite gear 35 is therefore moved through an are by the subsequent rotation of the gear 33. The shaft 331s moved at the same time" and turns the axle or shaft 29. This movement is relied upon 'for rotating an indicatoror counting dial'48 in the housing 21. I therefore provide a "disc-like cam wheel:49 to the right of the gear wheel 34 in Fig. '3 and fix it to the axle or shaft 29 for rotation thereby. The right'face of this wheel 43 carries an integral surface ring gear which meshes witha small pinion gear 5! fixed toa rotatable sleeve 52 to which the indicator dial 48 is fixed.- The sleeve 52 is mounted. on a fixed shaft 5 3 which extends through the pinion gear 5d and which has a bearing mounted around the shaft or axle .23 and includes an integral portion extending beyond the shaft 29. 'As "the satellite gear 35 moves clockwise in Fig. 2, it rotates the disc wheel 49 clockwise and also rotates the pinion gear 51 and sleeve 52, thel'atter of which has a bearing in the casing 23.

' The disc-like cam wheel '49 is provided with a peripheral cam surfaceoflarge diameter, ex-

tending counter-clockwise through 180? or more from the shoulder 54, normally engagedby a roller 35 carried on an arm 56 mounted on a shaft 51. The arm is integral with adog 38 extending over the peripheral cogs of the gear wheel 3'4. As soon as thesatellite gear 35] and its axle commence to move through an arc, the shoulder 5 4 on the cam wheel 49 is moved against the roller 55 and engages the dog 58 in the gear teeth of the wheel 34, thereby locking that wheel against further rotation andthus insuring accurate counting by the mechanism and permit ting. the free swinging of the roller during the counting period. The locking of the gear wheel 34 during the counting period dispenses with the necessity of relying upon the presence anduhcertainty of the braking action of the roller' 26 and allows the roller to be retracted at will when the cylinder and paper are reversed, f.

It is only-necessary that the satellite gear 34 andv the cam wheel 49 move throughan 'arc'of 180 or thereabouts inorder to count and indicate the necessary number of linesw'hich are displayed on the dial 48. As the cam wheel- 49 moves through that arc, it rotate againstthe biasing action of a tension spring 59 having the l i right end shown in Fig. 2 attached to the wheel,

while. the left end is attached to the. fixed. shaft 53. The spring '59 is mounted in a, circular shaped housing 60 attached to the shaft 59. After. the cam wheel has been rotated through an arc of the wheel 33 is released .for free rotation and the spring 5-3 rotates the cam wheel counter-clockwise and restores the dial 48 ,'the cam wheel 49' and the satellite gear 35 to their initial or starting position. As this occurs, the roller 55 passes over the shoulder 54 and unlocks thewheel 3'4. H I

Theforegoing operations described in connection with the movement of the satellite-gear involve other correlated actions for disconnecting and reconnecting the bevel gear 33 with respect to rotation by the cylinder I'B.

As shown in Figs. 4, 5 and 6, the bevel gear 33 is driven by the gear 38 which isrotatably mounted on the square shaft 23, the gear 38 being kept in mesh with the gear 33 and driven by a gear El integral with a sleeve 32 which fits shaft 23 and which is driven thereby. The gears 38and 6| have intermeshing facing gear teeth which when engaged provide a positive drive for the gear 38. The sleeve 62 and the gear 6| are urged toward the gear 38 by a light spring 63 bearing against 7 a stop Ell-mounted on the'shaft 23. Meansis provided for shifting the sleeve 62 to the right in Fig. 4 to take the gear 6| out of. mesh with the gear 38 and thereby discontinue the rotation of the gear 33 by the cylinder.

The mechanism for reciprocating the gear 6| and its sleeveBZ is shown in Figs. 4, 5 and 6 and includes an annular channel on the sleeve '62 formed by the surface 65 of the gear 6| and a ring flange 66 integral with the sleeve 62. A roller 61 carried on a pivoted arm or lever 68 operates between the surface 65 and the flange 66, the opposite end of the arm 68 being pivoted to a support 69 (Fig. 5) carried by the front of the casing 25. The lever 68 comprises a part of a snap acting mechanism actuated by a spring 10 under tension, one end of which is attached at the free end of the lever '68 while its other end is attached to the front of the casing 25.. When the free end of the lever 68 is moved across the center line extending through its point of attachment to the support 69 and the point of attachment of the spring 10 to the casing, the free end of the lever and the roller 6l'moves quickly in that direction to shift the sleeve 62 and its gear 6|.

In accordance with the present invention, this shifting operation is effected by cam members H and 12 attached to the opposite ends of the shaft 36, the cam member H being attached to the end of the shaft which extends beyond the satellite gear 35.

In a counting operation as described above, the satellite gear 35 moves clockwise as shown in Fig. 5, and as the cam H approaches the position of the sleeve 62 (Figs. 6 and 8) the sloping front edge 13 0f the cam engages a roller 14 mounted above the roller 61 on the trip mechanism, and moves the free end of the lever or arm 68 to the rightin Fig. 4 until the roller 51 moves across the center line and engages the flange66. At that instant the snap acting trip mechanismtakes the gear 6| out of engagement with the gear 38, thereby permitting free rotation of the differential gear 33 as well as the gear 38, by the action of the spring 59 which returns the satellite gear 35 to its initial or starting position.

As the satellite gear 35 approaches its initial or starting position atthe upper part of the mechanism, the opposite end of the shaft 36 carrying the cam 12 approaches the s1eeve62 (Fig. 9) and the sloping surface 15 of the cam l2 engages the roller 14 to move it and thefree end of the arm 68 to the left in Figs. 4 and 9, across the center line position, whereupon the roller 61 engages the surface65 and slides the sleeve 62 along the shaft 23 so that the gear 6| is almost instantly put in mesh with the gear 38. At the time the gears 38 and BI mesh, further movement of the shaft 36 in that direction is stopped. When this position of the shaft 36 is approached its upper end above the gear 35 moves into engagement with a friction spring 16 attached to the casing25 which retains the gear'35 in a steady position ready for the beginning of another counting or measuring operation. e w v When the reverse movement takes place outside of the counting range, and while the spring 16 is holding the gear 35, in place, (1) the roller 26 is lifted off the sheet, (2) the sheet moves back up the guide plate, (3) the gear merely rotates in place since it is driven by the cylinder and the differential gear 33, and (4) the roller 26 being disengaged, the gear. 34 and the roller 26 are rotated freely by the satellite gear 35.

Figs. 5 and 7 show the position of the gear 35 and the shaft 36, together with the cams'H and 12 attached thereto justafter the start of a counting operation. At this time, the dog 531s engaged in the gear 34. A torsional spring 51a. is mounted on the shaft 5'! fornormally holding the dog 58 away from the gear 34 and causes the roller tomove down overthe shoulder 54 when the satellitegear 35 returns to its initial position aftercarrying out a counting operation. H

Figs. 6 and 8 of the drawings show the positions of the shaft 36 and its associated elements at a point near the end of a counting operation. The cam H is preferably arranged with respect to the trip mechanism operated thereby so that as this cam approaches the roller 14, the actuation of the cylinder through one space will trip the mechanism and disconnect the gear wheel 33 from rotation by the square shaft 23. 1 The counting may be carried out in different ways for different machines. The initial position of the counter in the illustrative example is indicated in Fig. 1 as corresponding to line .20, as shown inthe window of the housing 21. This correspondsto a situation in which there are twenty lines or spaces remaining on the sheet of paper and as the counting starts the indicator will show the numbers successively from 20 down to zero, so that the operator will know at a glance exactly how many lines or spaces remain upon the sheet of paper being printed upon.

When the operator desires to commence a typing operation, the cylinder of the machine is given a slight turn in reverse'which instantly lifts the roller 26 and permits the free movement of the paper into position in back of and under the roller. Thereafter, when the operator rotates the paper into typing position with the cylinder the roller 26 is instantly brought against the paper, pressing it against the guide plate I9. Regardless of the length of the sheet of paper employed, the indicator dial will show the number ,20 until the end of the sheet of paper passes from' under the roller 26. At this point the counting operation proceeds in the manner described above. V 7 The mechanism of the present invention is designed to be automatic to the greatest extent possible, so that little or no attention will be required by the'operator. If desired,'however,

the front of the casing may carry a small slide or knob which is spring-biased" in one'direction and whiclrmay be actuated instantly by the operator to'trip the snap acting mechanism for releasing the gear wheel 33. This, however, is not regarded as "necessary, although it may be possible that an operator, desiring to do so, may remove a typed sheet from the machine before the counting mechanism has progressed through to zero to trip the snap acting means. The mechanism may be operated to the trip point by merely rotating the cylinder forward. During ordinary operation, however, even though the page is not typed to the end, the rotation of thecylinder to remove the paper will carry the counting to the end and trip the snap acting mechanism to release the gear wheel 33.

In order to simplify the showing in the drawings, certain standard elements which would be normally included are. not shown. For example, it will be understood that the gealiwheels 33 and 34 carried on the shaft 29 will be held'in place by suitable spacer collars and the same is true of other elements mounted on this shaft and the shaft carrying the roller 36. The collars between the gear wheels 33 and 34, of course, will serve as spacers and be fixed to the shaft 29 while the gears themselves are free to rotate thereon. Furthermore, the swing armscarrying the shaft on which the roller 26 is mounted will carry relatively long spacer collars which will-contribute to the rigidity of the shaft and hold the various elements in the positions shown in the drawings.

Figs. and 11 show a modified form of counting and indicating mechanism which is the same as that described above, except for'the means employed for driving it from. the cylinder or platen. In these views the elements shown corresponding to those described above are indicatedby the same reference characters followed by the letter a.

The casing 25a shown in Fig. 10 may be secured to the carriage by a clamp or other suitable means, not shown, while the square shaft 23a is short and is rotatably mounted in bearings in opposite sides of the casing. O-ne endof this shaft extends to one side of the casing and has fixed thereto a roller ll of polygonal crosssection mounted in engagement with the surface of the cylinder 6a and'driventhereby. Each fiat surface 18 of the roller Tl may represent a single space movement of the cylinder, or the width of each surface 13 may correspond to the distance through which the periphery of the cylinder moves in one step. shape of the roller 11 insures a more positive drive than if it were cylindrical.

The roller. '11, as wellas the other roller use with either form of the device is advantageously made of suitable rubber material such as that used for making the cylinder or platen.

The device or mechanism forming thesubject of the present invention has been described in connection with its preferred use with typewriters and other printing machines to which it is attachable. It is to be understood, however, that the mechanism may have other uses for counting and measuring spaces or distances and for showing to an operator the position or stage of operation of a machine or device when it approaches a critical or important condition.

While specific structures have been shown and described for various parts of the apparatus of the present invention, it is to be understood that other equivalent or alternative structures may be employed. For example, instead of having the shaft 36, a disc may be used which is fixed to the shaft extending through the gear wheels 33 and 34, and other connections may be made for operating the indicator and counting means. The indicator may also have a different form and may be operated more directly by the movement of the gear 35 around the gears 33 and 34. Other changes may be made as contemplated within the scope of the appended claims.

I claim:

1. In a sheet-end indicator and space counting mechanism for printing machines having a cylinder and a guide plate cooperating therewith, a roller biased toward the guide plate and adapted to engage and bear against the surface of a sheet of paper passing over said plate and around said cylinder, said roller being adapted to be rotated by the movement of the paper over the surface of the plate, an indicating and counting means, a control mechanism operatively asso ciated with the cylinder for moving the indicating means in one direction as the cylinder is rotated during a typing operation, means operatively associated with the roller and said con- The polygonal 10 I trol mechanism for annulling the action of the cylinder and said control mechanism to move the indicating means during the time the roller is rotated by the sheet of paper, and means actuated by'the cylinder and responsive to its reverse rotation for disengaging the roller from the sheet of paper, whereby the sheet of paper is freely movable along said plate away from the cylinder during the reverse rotation of the cylinder.

2. A: mechanism as claimed in claim l in which said control mechanism comprises two parallel gear wheels of equal diameter and a pinion gear meshing therewith, said gear wheels being respectively connected for rotation by the cylinder and roller, and means actuated by the pinion gear .for moving the indicating means.

3. A'mechanism as claimed in claim 2 char acterized by including means operatively associated with the pinion gear for locking the gear wheel connected with the roller. 1

a. A mechanism as claimed in claim 3 char acterized by includinga first shaft extending axially through the gear wheels and upon which said wheels are rotatable, a second shaft extending from t hepinion'gear and fixed to the first shaft, and means actuated by the first shaft for moving the indicating means; Y 7

5. A mechanism as claimed in claim 4, characterized 'by including a cam wheel fixed to the first'shaft outside said gear wheel connected to the roller, and means actuated by the cam wheel for locking said gear wheel when said pinion gear is moved to in turn move the indicating means.

6'. A mechanism as claimed in claim 5, characterized by including means actuated upon movement of said pinion gear through a predetermined are for disconnecting the cylinder from the gear wheel connected thereto, and means for rotating said disconnected gear wheel to return the pinion gear to its initial position.

7. A mechanism as claimed in claim 6, characterized by including means actuated upon movement of said pinion gear to itsinitial position for reconnecting the cylinder with its gear wheel.

8. In a mechanism of the type described for printing machines having a cylinder and a guide plate cooperating therewith, a roller biased toward the guide plate and adapted to engage and bear against the surface of a sheet of paper passing over said plate and around said cylinder, said roller being adapted to be rotated by the movement of the paper over the surface of the plate, an indicating means, a differential mechanism including two parallel gear wheels of equal diameter meshing with a pinion gear, means for driving one of said wheels by the cylinder for in turn moving the indicating means in one direc tion as the cylinder is rotated during a typing operation, means operatively associated with the roller for driving the other wheel in the opposite direction at the same rate as the first wheel during the time the roll-er is rotated by the sheet of paper, means actuated by the pinion gear for moving the indicating means, means responsive to the movement of the pinion gear in one direction around the gear wheels for disconnecting the cylinder from its gear wheel, and means for thereafter returning said pinion gear to its initial position.

9. A mechanism as claimed in claim 8, characterized by including means responsive to the movement of the pinion gear to its initial position for reconnecting the cylinder with its gear wheel.

10.- A mechanism as claimed in claim 8, characterized by including means for automatically moving the roller away from the guide plate in response to the reverse rotation of the platen.

11. A mechanism as claimed in claim 1 in which said control mechanism comprises two parallel gear wheels of equal diameter, a pinion gear meshing therewith, said gear wheels being respectively connected for rotation by the cylinder'and the roller, means actuated by the pinion gear for moving the indicating means, and means operatively associated with the pinion gear for locking and unlocking the gear wheel connected with the roller.

12. A mechanism as claimed in claim 1 in which said control mechanism comprises two parallel gear wheels of equal diameter, a shaft extending axially through said gear wheels and upon which they are rotatably mounted, said gear wheels being respectively connected for rotation by-the cylinder and roller, a pinion gear meshing with said gear wheels, means interconnecting said pinion gear with said shaft for rotating said shaft, and means actuated by the rotation of said shaft for moving the indicating means.

13. A mechanism of the type described, comprising a roller adapted to engage and bear against the surface of a movable member and be driven thereby, a counting means, a second driving means, a difierential mechanism operatively associated with the second driving means for moving the counting means in one direction, means operatively associated with the roller and said differential mechanism 'for annulling the action of the second driving means and said mechanism to operate the counting means during the time the roller is rotated by the movable member, and means actuated by the second driving means and responsive to its reverse rotation for disengaging the roller from the movable member. I

14. 'A counting device comprising a differential mechanism including a pair of parallel wheels and a satellite wheel engaging saidwheels and'driv'en thereby, a counting means actuated by the movement of said wheel around said pair of wheels, a first driving means for revolving one of said pair of wheels, a second driving means for revolving the other of said pair of wheels, means responsive to the braking or stopping of the first driving means for locking the wheel of said pair revolved thereby, whereby operation of thesecond driving means effects movement of the satellite wheel around said pair of wheels and drives the counting means, means actuated by the movement of the satellite wheel through an are less than a circle for disconnecting the driving connection between the second driving means and the parallel wheel driven thereby, and means for reversing the rotation of the said parallel wheel and thereby reversing the direction of movement of said satellite wheel.

PAUL F. GUERIN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,836,655 Dunford Dec. 15, 1931 1,993,038 Munk Mar. 5, 1935 

